The discovery of the cell death processes that determine the number of 'regulatory T cells' an individual has could one day lead to better treatments for immune disorders.
Regulatory T cells are members of a group of immune cells called T cells. Most T cells actively respond to clear the body of infections. By contrast, regulatory T cells are considered to be immune suppressing cells because they can 'switch off' an immune response to a particular molecule. This immune suppression is important for preventing inappropriate immune attack of the body's own tissues, which is the underlying cause of autoimmune diseases such as lupus and type 1 diabetes.
A shortage of regulatory T cells is linked with the development of autoimmune and inflammatory conditions, while some people with higher than normal numbers of regulatory T cells cannot fight infections properly.
Dr Daniel Gray and Ms Antonia Policheni from the Walter and Eliza Hall Institute's Molecular Genetics of Cancer and Immunology divisions made the discovery about how regulatory T cell numbers are controlled as part of an international team of researchers jointly led by Dr Gray and Dr Adrian Liston who is head of the Flanders Institute for Biotechnology (VIB) Laboratory for Autoimmune Genetics at the University of Leuven, Belgium. They found that regulatory T cells are constantly being produced in the body, but their numbers are held steady by a process of cell death. The findings are published today in the journal Nature Immunology.
Cell death, or apoptosis, is important in many immune cell types for the removal of excess, defective or damaged cells. The decision of these cells on whether to live or die is controlled by a family of proteins called the 'Bcl-2 protein family'. This includes proteins that can either promote cell survival or trigger cell death, in response to many different stimuli.
Dr Gray said the team had discovered that Bcl-2 family proteins were important determinants of regulatory T cell numbers. "Regulatory T cell death is highly dependent on the activity of two opposing Bcl-2 family proteins, called Mcl-1 and Bim," he said. "Mcl-1 is required for regulatory T cell survival, allowing them to suppress unhealthy immune responses, while Bim triggers the death of regulatory T cells. Without Mcl-1 activity, regulatory T cell numbers fall, provoking lethal autoimmune disease. Conversely, if Bim activity is lost, regulatory T cells accumulate in abnormally high numbers."
Dr Liston said the finding was exciting, because it opened up new ways to control regulatory T cell numbers in disease. "Already, there is considerable interest in a new class of agents, called 'BH-3 mimetics' that target Bcl-2-like molecules including Mcl-1," he said. "If agents that can influence regulatory T cell survival can be developed, we could see new ways to suppress autoimmune disease, by boosting regulatory T cell numbers, or to enhance beneficial immune responses, by silencing regulatory T cells."
The research was funded by the Australian National Health and Medical Research Council, the Victorian government, the European Union, the Belgian Government, and the VIB.
Liz Williams | EurekAlert!
Don't Give the Slightest Chance to Toxic Elements in Medicinal Products
23.03.2018 | Physikalisch-Technische Bundesanstalt (PTB)
North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy